The terminals of batteries such as used in motor vehicles are subject to corrosion and deterioration when exposed to the weather. The corrosion and deterioration shortens the usable life of the cable terminations and reduces the conductivity of the connection between the battery and the cable. Furthermore, the batteries of vehicles store substantial amounts of electrical energy and arcing and discharge of the battery can occur if a foreign object contacts the terminal.
To reduce the exposure of the terminal and the cable termination to the ambient and to protect against contact with foreign objects, the battery cables and the metal plate which fits over the battery terminal may be potted in an insulating elastomeric material. In this case, only a portion of the connector plate which surrounds an aperture through the termination and the terminal are left exposed, and these parts are covered by an insulating cap fitted over the terminal.
In order to hold the cap in assembled relationship over the terminal it was previously the practice to provide a tight fit between the cylindrical inner surface of the cap and the outer surface of a tubular projection of the elastomeric material part of the termination. One or more ridges on one of these surfaces and corresponding grooves on the other of these surfaces which fit into one another have been used to retain the cap in place.
The terminal extends outside the distal end of the tubular section of the connector in order that it may be reached with a conventional wrench for removing the cable. As a result, only a portion of the hollow cylindrical section of the cap is engaged by the tubular section of the cable termination. When batteries are installed in trucks and the like, they are subjected to mechanical shocks and vibrations which, over a long period of time, may cause the caps to disconnect and allow the battery terminal to be exposed.
It is, therefore, desireable to provide a cap which is secured to the cable termination and to the terminal itself along the entire depth of the cylindrical section of the cap, so as to maximize the surface area by which the cap is retained over the terminal.